1. Field of the Invention
The present invention relates to a tray for storing and organizing optical ribbon fiber splices and an excess length of the optical ribbon fiber easily. More particularly, it relates to a tray for splicing optical ribbon fibers capable of holding firmly splices used in the splicing between the optical ribbon fibers consisting of multifiber (i.e., 4 to 12 cores), improving accommodation density for the optical ribbon fiber splices and excess length by using the new splice arrangement plate structure.
2. Description of Related Art
Generally, as a result of spread of the high-speed broadband telecommunication, when optical lines are supplied to all homes, many optical fibers are required as well as the copper lines. Therefore, when it is intended to construct subscriber lines by means of the optical cable, an optical ribbon cable which is made of a plurality of optical fibers has been developed and used. The optical ribbon cable is manufactured by a plurality of cores in a single body, so that a volume of the optical cable can be minimized and a plurality of cores can be integrated. Presently, the optical ribbon fiber made of optical fiber having 4 cores, 8 cores or 12 cores is used. Further, a plurality of splicing points and connecting points are required so that the the optical ribbon fiber cable is supplied to specific position.
In this case, since a splicing point affects performance and a degree of the reliance for all optical telecommunication lines, the splicing point should be protected from an extraneous mechanical shock perfectly. Further, the excess length of the optical fiber used in the splicing should be arranged to distinguish from each other easily so that a re-splicing or repair work for the excess length is convenient, and be stored securely.
Therefore, the tray is indispensable for protecting the splices and storing the excess length. By the way, in case the optical ribbon fiber, since sizes and shapes of fibers, a method of fixing the splice, and a method of arranging the excess length are different from those in a single optical fiber, there is a problem that the tray for the single optical fiber cannot be used for the optical ribbon fiber as it is. Therefore, there is needed a new product which adapts a method of storing and organizing the optical ribbon fiber splices and the excess length according to a new aspect. Further, since most of the splicing works are accomplished in a small space such as a man-hole, the splicing products need to be minimized fit in a small space. Furthermore, since the entire size of the splicing products depends on an accommodation ability of the splices, the tray needs to be minimized and a plurality of splice portions needs to be accommodated in the tray at a high density.
Most of the trays for storing and organizing optical ribbon fiber splices according to the prior art are made by modifying partially of the tray for a single optical fiber.
However, since the optical ribbon fibers have width and length different from each other, it is difficult to fix the splice and arrange the excess length in a single plane. Particularly, it is very difficult to access separately the specific optical ribbon fiber if repair is needed.
U.S. Pat. No. 5,323,480 entitled "Fiber Optical Splice Closure" discloses a structure capable of accommodating the optical ribbon fiber as well as a single optical fiber. In this case, since arrangement work of the excess length of the optical ribbon fiber should be performed in a single plane, when a plurality of optical ribbon fibers having a long or short excess length are made by re-splicing work, there is a problem that the excess length is twisted and the arrangement of the excess length cannot be neatly accomplished. Further, since the accommodation density of the splice and excess length is diminished, a plurality of spliced portions cannot be accommodated.
U.S. Pat. No. 5,278,933 entitled "Fiber Optic splice Organizer and Associated Method" discloses an apparatus capable of arranging a splice of the optical ribbon fiber three-dimensionally. However, since a large portion of a space for arranging the excess length isn't utilized, a degree of the space utility degrades. Even though only one optical ribbon fiber should be re-spliced, the operator should untie all excess length of optical ribbon fiber accommodated in the apparatus. Further, the number of the splice accommodated in a tray is limited to a method applied to arrangement of the excess length, and it is difficult to accommodate a plurality of the trays in an splice closure because a volume of a tray is large.
A few publications published in Japan (i.e., A New Optical Slack Fiber Accommodation Block For 800-Fiber Fusion Splices, The Transaction of the IECE of Japan. Vol. E 69, No. 4 April 1986 p360, and A New High-Density Cylindrical Accommodation Block for a Large Number of Optical Fiber Splices, The Transaction of the IECE of Japan. Vol. E69, No. 4 April 1986 p363) disclose apparatus capable of improving accommodation density by using a plastic sheet instead of the tray. In these cases, a plurality of the splices and the excess length are attached to the plastic sheet by an adhesive tape.
However, since a plurality of the plastic sheets are stacked, when an operator works on a splice which is attached to a specified sheet positioned in a middle portion, it is difficult for an operator to access to the objective splice. Furthermore, since a sheet-shaped plastic is used as the tray for supporting-protecting optical fiber, there is a problem that the splice portion and the optical ribbon fiber cannot be protected from an extraneous vibration and shock completely.